Post-marketing Surveillance Study for the Safety of Efluelda Tetra Pre-filled Syringe.

Post-marketing Surveillance Study for the Safety of Efluelda Tetra Pre-filled Syringe, a High-dose Quadrivalent Influenza Vaccine Administered to Adults 65 Years or Older in the Republic of Korea.

To investigate the incidence of adverse events (AEs) and adverse drug reactions (ADRs) occurred following administration of Efluelda Tetra in adults aged 65 years or older under routine clinical practice, as per approved indications.

The study duration of each participation will be approximately 28 to 35 days. In the event that Visit 2 is not made, the study duration would be extended to 36 to 42 days.

Study Overview

• Status: Not yet recruiting
• Conditions: Influenza (Healthy Volunteers); Immunization
• Intervention / Treatment: Biological: Efluelda Tetra Pre-filled syringe

• Study Type: Observational
• Enrollment (Estimated): 670

Contacts and Locations

• Study Contact: Name: Trial Transparency email recommended (Toll free for US & Canada); Phone Number: option 6 800-633-1610; Email: contact-us@sanofi.com

Study Locations

• South Korea
  • Seoul-teukbyeolsi
    • Seoul, Seoul-teukbyeolsi, South Korea, 07441
      • Investigational Site Number : 001

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Older Adult
• Accepts Healthy Volunteers: Yes

• Sampling Method: Non-Probability Sample

Study Population

Investigators will recruit participants after vaccination with Efluelda Tetra as per routine healthcare visits and according to approved local product labeling, at study centers (general hospitals or clinics located in Korea).

Description

Inclusion Criteria:

• Adults aged 65 years or older on the day of enrollment
• The informed consent form has been signed and dated
• Receipt of 1 dose of Efluelda Tetra on the day of enrollment according to the approved local product label

Exclusion Criteria:

• Previous history of enrollment in this study
• Participation at the time of study enrollment (or in the 4 weeks preceding the enrollment) or planned participation during the present study period in a clinical study investigating a vaccine, drug, medical device or medical procedure

Study Plan

How is the study designed?

Number of groups / cohorts

1

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
Efluelda group; A single dose of 0.7 mL is administered as approved by MFDS.	Biological: Efluelda Tetra Pre-filled syringe; Suspension for injection in a pre-filled syringe

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Time Frame
Occurrence of solicited (pre-listed in the participant's diary card [DC] and case report form) injection site and systemic reactions	From baseline up to 7 days after vaccination
Occurrence of unsolicited AEs and ADRs	From baseline up to Visit 2 (28-35 days) after vaccination
Occurrence of unexpected AEs and ADRs	From baseline up to participant's last contact after vaccination (36-42 days)
Occurrence of serious adverse events (SAEs) and serious adverse drug reactions (SADRs)	From baseline up to participant's last contact after vaccination (36-42 days)
Occurrence of AE of special interest (AESI)	From baseline up to participant's last contact after vaccination (36-42 days)

Collaborators and Investigators

• Sponsor: Sanofi
• Investigators: Study Director: Clinical Sciences & Operations, Sanofi

Study record dates

Study Major Dates

• Study Start (Estimated): October 1, 2026
• Primary Completion (Estimated): December 31, 2027
• Study Completion (Estimated): January 31, 2028

Study Registration Dates

• First Submitted: November 15, 2024
• First Submitted That Met QC Criteria: November 15, 2024
• First Posted (Actual): November 19, 2024

Study Record Updates

• Last Update Posted (Actual): December 15, 2025
• Last Update Submitted That Met QC Criteria: December 5, 2025
• Last Verified: December 1, 2025

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Respiratory Tract Infections; Infections; Orthomyxoviridae Infections; RNA Virus Infections; Virus Diseases; Respiratory Tract Diseases; Influenza, Human
• Other Study ID Numbers: QHD00024 (Sanofi Identifier); U1111-1251-6083 (Registry Identifier: ICTRP)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES
• IPD Plan Description: Qualified researchers may request access to patient level data and related study documents including the clinical study report, study protocol with any amendments, blank case report form, statistical analysis plan, and dataset specifications. Patient level data will be anonymized and study documents will be redacted to protect the privacy of trial participants. Further details on Sanofi's data sharing criteria, eligible studies, and process for requesting access can be found at: https://vivli.org

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: Yes